summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/tsc.c
diff options
context:
space:
mode:
authorH. Peter Anvin <hpa@linux.intel.com>2010-10-02 03:18:11 +0400
committerH. Peter Anvin <hpa@linux.intel.com>2010-10-02 03:18:11 +0400
commit86ffb08519d6fe1e9c4fe5a110ffa5fcb868cb1c (patch)
treede2fe9f6c122dc34c825e60619560452132f0cf2 /arch/x86/kernel/tsc.c
parent23ac4ae827e6264e21b898f2cd3f601450aa02a6 (diff)
parentaeb9c7d618264dcf6eea39142fefee096c3b09e2 (diff)
downloadlinux-86ffb08519d6fe1e9c4fe5a110ffa5fcb868cb1c.tar.xz
Merge remote branch 'origin/x86/cpu' into x86/amd-nb
Diffstat (limited to 'arch/x86/kernel/tsc.c')
-rw-r--r--arch/x86/kernel/tsc.c58
1 files changed, 0 insertions, 58 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 26a863a9c2a8..4496315eb224 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -892,60 +892,6 @@ static void __init init_tsc_clocksource(void)
clocksource_register_khz(&clocksource_tsc, tsc_khz);
}
-#ifdef CONFIG_X86_64
-/*
- * calibrate_cpu is used on systems with fixed rate TSCs to determine
- * processor frequency
- */
-#define TICK_COUNT 100000000
-static unsigned long __init calibrate_cpu(void)
-{
- int tsc_start, tsc_now;
- int i, no_ctr_free;
- unsigned long evntsel3 = 0, pmc3 = 0, pmc_now = 0;
- unsigned long flags;
-
- for (i = 0; i < 4; i++)
- if (avail_to_resrv_perfctr_nmi_bit(i))
- break;
- no_ctr_free = (i == 4);
- if (no_ctr_free) {
- WARN(1, KERN_WARNING "Warning: AMD perfctrs busy ... "
- "cpu_khz value may be incorrect.\n");
- i = 3;
- rdmsrl(MSR_K7_EVNTSEL3, evntsel3);
- wrmsrl(MSR_K7_EVNTSEL3, 0);
- rdmsrl(MSR_K7_PERFCTR3, pmc3);
- } else {
- reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i);
- reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i);
- }
- local_irq_save(flags);
- /* start measuring cycles, incrementing from 0 */
- wrmsrl(MSR_K7_PERFCTR0 + i, 0);
- wrmsrl(MSR_K7_EVNTSEL0 + i, 1 << 22 | 3 << 16 | 0x76);
- rdtscl(tsc_start);
- do {
- rdmsrl(MSR_K7_PERFCTR0 + i, pmc_now);
- tsc_now = get_cycles();
- } while ((tsc_now - tsc_start) < TICK_COUNT);
-
- local_irq_restore(flags);
- if (no_ctr_free) {
- wrmsrl(MSR_K7_EVNTSEL3, 0);
- wrmsrl(MSR_K7_PERFCTR3, pmc3);
- wrmsrl(MSR_K7_EVNTSEL3, evntsel3);
- } else {
- release_perfctr_nmi(MSR_K7_PERFCTR0 + i);
- release_evntsel_nmi(MSR_K7_EVNTSEL0 + i);
- }
-
- return pmc_now * tsc_khz / (tsc_now - tsc_start);
-}
-#else
-static inline unsigned long calibrate_cpu(void) { return cpu_khz; }
-#endif
-
void __init tsc_init(void)
{
u64 lpj;
@@ -964,10 +910,6 @@ void __init tsc_init(void)
return;
}
- if (cpu_has(&boot_cpu_data, X86_FEATURE_CONSTANT_TSC) &&
- (boot_cpu_data.x86_vendor == X86_VENDOR_AMD))
- cpu_khz = calibrate_cpu();
-
printk("Detected %lu.%03lu MHz processor.\n",
(unsigned long)cpu_khz / 1000,
(unsigned long)cpu_khz % 1000);